More than two months ago I wrote about how to recycle properly; and in the article I mentioned that I would like to focus on each part of the waste separately, because although we know where to put a plastic wrapper, an old notebook or a glass bottle, most can't imagine what happens to the products after we throw them in the coloured bin.

So today I'll focus on plastic, because I assume that everyone cares about it the most. This topic is very extensive and you could write a few posts about it, but I tried to keep it short and simple to keep you from getting bored.

WHAT IS PLASTIC?

Plastic is a synthetic or semi-synthetic organic material made primarily of petroleum. Its popularity has grown over the past century, when this material has proven to be ideal for making many products. The problem is that it's from a non-renewable source, so it'll run out of its stock at some point. At the current consumption of 33 tons of oil per person it'll be in within 13 years.

Plastics are divided into seven groups – and according to that they have a small number in the middle of a recycling logo:

The interest in recycling appeared in the 1960s, but the first recycling line was opened in 1972 in Pennsylvania. Since then, hundreds of such factories have been created worldwide.

RECYCLING

Yellow containers are used to collect plastic waste – and in this article you will find out what belongs to them and what doesn't (but check it with your local system, because this applyies mainly to Slovakia). When the container is full, they'll take it to a sorting line where they'll sort the plastics by category. At this stage, they also remove products that don't belong to the recycling or are contaminated. These centers are also equipped with a "washing machine", where the waste is properly washed (but you should still rinse the yoghurt and other food containers anyway, since dirty packaging cannot be thrown into a recycling container).

This is followed by crushing the plastic into small pieces. They re-weigh it to avoid mixing different types of plastic. And again they clean and dry it to be 100 percent sure that there're no impurities in the plastic "flakes". Only then can they melt and mold it or the flakes serve as a secondary material to other products – in addition to recycled material, new plastic from oil must be added to many plastic products. As for PET bottles, they turn them into long fibers that make carpets or clothes. Almost never the original plastic product will become the same that entered the recycling process.

But it's not that simple. Only about 50% of the plastic in the yellow container can be recycled. The rest goes to the incinerator because it's contaminated or contains various other materials. Considerable amount of waste is also generated during recycling.

However, incineration is not ideal because, since plastic products contain various colorants or plasticizers in which heavy metals such as cadmium or zinc are present, they're released into the air and remain in the ash. In addition, hydrocarbons and phthalates are released which can also accumulate in the human body. In case of incomplete combustion, toxic carbon monoxide or carcinogenic vynil chloride is produced; burning PVC makes hydrochloric acid, which irritates the respiratory tract. Micro-plastics are equally dangerous – they're produced by washing clothes made of polyester, by the action of natural elements on plastic products, or they're intentionally used in cosmetics (in peelings or toothpastes). According to estimates, there're up to 51 trillion micro-plastics in the ocean – fish and marine animals eat them, and later do people. Micro-plastics are already present in drinking water.

But plastic cannot be recycled indefinitely – on average it's about five to seven times. Indeed, by repeated heat treatment, its positive properties are lost; and quality is also reduced by use.

YES OR NO?

Plastic also has its advantages. It's lightweight, durable, easily and quickly moldable and lasts a long time. Thanks to these characteristics, it has become an ideal material for producing products that would otherwise not exist – such as safety helmets or cables at the bottom of the oceans that connect us to every corner of the world.

The problem is that during the production and popularization of plastic products no one expected for it to become a global phenomenon – and that they'd be a significant threat to the environment. The incineration of plastics negatively affects the air, 8 million tons of plastic, which end up in the ocean every year, kills marine animals, and products that end up in the landfill discharge toxic substances into groundwater.

Although the recycling process is far from perfect, it has an environmental value. Plastic recycling saves up to 97% of energy compared to primary production, and this waste also doesn't end up at sea or a landfill.

However, it's extremely important that we reduce our consumption of plastic. The fact that only 7% of the weight of municipal waste is plastic may not seem like much, but it's only because it's very light compared to other materials. Every year everyone produces up to an incredible 280 kilograms of plastic waste.

Only 40% of plastic waste is packaging. Package-free stores are all around the world – both in smaller or bigger cities – and the number of them only increases. If you buy basic foods without unnecessary plastic packaging, you can reduce the amount of generated waste by up to a third. The same applies to drugstores or household products. There are a lot of possibilities – you'll just have to want to do it.